1. Field of the Invention
The present invention relates to an apparatus and method of manufacturing a drum, and more particularly, to an apparatus and method of manufacturing a drum for a dryer so as to prevent noise and vibration.
2. Discussion of the Related Art
In general, a dryer is an apparatus for drying laundry, such as clothes, that are placed inside a cabinet, and where hot air is heated by an electric heater or a gas combustion device. A demand for dryers has increased continuously.
FIG. 1 is a disassembled perspective view illustrating a dryer in accordance with the related art.
As shown in FIG. 1, a related art drum 1 is provided inside of a cabinet (not shown), where the cabinet forms the exterior of the dryer. The drum 1 has a cylindrical shape with open front and rear sides. Also, a belt groove 2 is provided on an outer surface of the drum 1, on which a belt (not shown) connected to a motor is wound.
Furthermore, the drum 1 has a chamber 5 that receives laundry and has a plurality of lifts 6 protruding from an inner surface thereof. That is, when the drum 1 is rotated, the lifts 6 are provided to lift and drop the laundry, whereby the laundry is turned over. Accordingly, the laundry is dried in a short time. Also, a front support 7 and a rear support 9 are respectively provided in the front and rear sides of the drum 1. The front and rear supports 7 and 9 simultaneously close and support the front and rear sides of the drum 1.
Meanwhile, a sealing member 10 is provided between the drum 1 and the front support 7/rear support 9. A plurality of rollers (not shown) are also provided between the front support 7 and the rear support 9 which correspond to the front and rear sides of the drum 1 so as to support the drum 1.
An opening 8 is also provided in the front support 7, whereby the chamber 5 communicates with the outside through the opening 8. The opening 8 is selectively closed or opened with a door (not shown). In the rear support 9, a supply duct 12 communicates with the chamber 5, whereby heated air is provided to the chamber 5 through the supply duct 12.
Also, an outlet assembly 13 is provided in one side of the front support 7 corresponding to a lower part of the opening 8 provided in the front support 7, whereby air from the chamber 5 is discharged through the outlet assembly 13. The outlet assembly 13 is provided with a filter 14 for filtering foreign particles (for example, dust or thread) from the air discharging through the chamber 5.
The outlet assembly 13 communicates with an exhaust duct 15 where the filter 14 is provided in the exhaust duct 15. Also, the exhaust duct 15 is connected with a fan housing 18. Here, air inside the chamber 5 flows along the exhaust duct 15 and the fan housing 18 as a fan 17 mounted inside the fan housing 18 is operated. The fan 17 is a centrifugal fan for improving space efficiency. However, it is possible to use an axial fan.
Additionally, one side of the fan housing 18 communicates with the exhaust duct 15, and another side of the fan housing 18 communicates with an exhaust pipe 19. Accordingly, the air passing through the fan housing 18 is exhausted to the outside through the exhaust pipe 19.
Meanwhile, the supply duct 12 communicates with a guide funnel 16. The guide funnel 16 is formed in a truncated conic shape so as to guide the heated air to the supply duct 12. The guide funnel 16 is provided with a gas combustion device 20 having a valve, a mixing pipe, and an igniter. Herein, the valve is connected to a gas pipe so as to control a gas provision, the mixing pipe mixes the gas sprayed from a gas nozzle to the air, and the igniter ignites the mixed gas.
A method of manufacturing the drum applied to the related art dryer will be described as follows.
Referring to FIG. 2, a metal plate such as a stainless steel plate is rolled, and a seam is welded. Then, a central diameter of the drum is expanded while maintaining a diameter at both ends of the drum. The central diameter of the drum is expanded using a method of pressing an inner side of the drum toward the outside with a plurality of dies. After that, a bead process is performed in a central part of the drum. That is, a plurality of grooves are provided along an outer surface of the drum for strengthening the drum. Also, a hemming process is performed using a method of bending the end at both ends of the drum.
The method of manufacturing the drum for the dryer according to the related art has the following disadvantages. The central part of the drum is expanded with the die provided in the inner surface of the drum. That is, the die presses the central part of the drum toward the outside. On completion of the manufacturing process steps of the drum, traces of the dies may remain on the drum when the dies are separated from the central part of the drum, thereby deteriorating the exterior of the drum. Also, if the circular shape of the drum is damaged, it is impossible to obtain uniform rotation inertia, thereby generating noise and vibration during rotation of the drum.